Organic light-emitting diodes (OLED) have characteristics, such as self-luminescence, high brightness, wide viewing angle, high contrast, low energy consumption, etc., and have attracted much attention and have widely been used in mobile phone screens, computer monitors, full-color televisions, etc. In an OLED encapsulation structure or an OLED display device, light is emitted from a side of an encapsulation cover plate or the side, opposite to the encapsulation cover plate, of a base substrate. The light emitted by an OLED element is in all directions, and passes through the space between the encapsulation cover plate and an OLED substrate before exiting from the encapsulation cover plate or from the base substrate as well as two surfaces of the encapsulation cover or the plate base substrate.